Bifunctional or amphoteric photoacids simultaneously present donor (acidic) and acceptor (basic) properties making them useful tools to analyze proton transfer reactions. In protic solvents, the proton exchange between the acid and the base is controlled by the acidity or basicity strength and typically occurs on two different pathways known as protolysis and hydrolysis. We report here how the addition of a formate base will alter the relative importance of the possible reaction pathways of the bifunctional photoacid 7-hydroxyquinoline (7HQ), which has been recently understood to predominantly involve a hydroxide/methoxide transport mechanism between the basic proton-accepting quinoline nitrogen site toward the proton-donating OH group with a time constant of 360 ps in deuterated methanol (CD3OD). We follow the reaction dynamics by probing the IR-active marker modes of the different charged forms of photoexcited 7HQ, and of formic acid (HCOOD) in CD3OD solution. https://www.selleckchem.com/products/kpt-330.html A comparison of the transient IR spectra as a function of formate concentration, and classical molecular dynamics simulations enables us to identify distinct contributions of "tight" (meaning "contact") and "loose" (i.e., "solvent-separated") 7HQ-formate reaction pairs in our data. Our results suggest that depending on the orientation of the OH group with respect to the quinoline aromatic ring system, the presence of the formate molecule in a proton relay pathway facilitates a net proton transfer from the proton-donating OH group of 7HQ-N* via the methanol/formate bridge toward the quinoline N site.Inspired by the unique biological microenvironments of eukaryotic cells, hollow capsules are promising to immobilize enzymes due to their advantages for physical protection and improved activity of enzymes. Herein, we report a facile method to fabricate silica (SiO2) capsules using zeolitic imidazole framework-8 nanoparticles (ZIF-8 NPs) as templates for enzyme immobilization and catalysis. Enzyme-encapsulated SiO2 capsules are obtained by encapsulation of enzymes in ZIF-8 NPs and subsequent coating of silica layers, followed by the removal of templates in a mild condition (i.e., ethylenediaminetetraacetic acid (EDTA) solution). The enzyme (i.e., horseradish peroxidase, HRP) activity in SiO2 capsules is improved more than 15 times compared to that of enzyme-loaded ZIF-8 NPs. Enzymes in SiO2 capsules maintain a high relative activity after being subjected to high temperature, enzymolysis, and recycling compared to free enzymes. In addition, multienzymes (e.g., glucose oxidase and HRP) can also be coencapsulated within SiO2 capsules to show a reaction with a high cascade catalytic efficacy. This work provides a versatile strategy for enzyme immobilization and protection with potential applications in biocatalysis.Silver, king among plasmonic materials, features low inelastic absorption in the visible-infrared (vis-IR) spectral region compared to other metals. In contrast, copper is commonly regarded as too lossy for actual applications. Here, we demonstrate vis-IR plasmons with quality factors &gt;60 in long copper nanowires (NWs), as determined by electron energy-loss spectroscopy. We explain this result by noticing that most of the electromagnetic energy in these plasmons lies outside the metal, thus becoming less sensitive to inelastic absorption. Measurements for silver and copper NWs of different diameters allow us to elucidate the relative importance of radiative and nonradiative losses in plasmons spanning a wide spectral range down to less then 20 meV. Thermal population of such low-energy modes becomes significant and generates electron energy gains associated with plasmon absorption, rendering an experimental determination of the NW temperature. Copper is therefore emerging as an attractive, cheap, abundant material platform for high-quality plasmonics in elongated nanostructures.Solvent-solute interactions in precursor solutions of lead halide perovskites (LHPs) critically impact the quality of solution-processed materials, as they lead to the formation of a variety of poly-iodoplumbates that act as building blocks for LHPs. The formation of [PbI2+n]n- complexes is often expected in diluted solutions, while coordination occurring at high concentrations is not yet well understood. In a combined ab initio and experimental work, we demonstrate that the optical spectra of the quasi-one-dimensional iodoplumbate complexes PbI2(DMSO)4, Pb2I4(DMSO)6, and Pb3I6(DMSO)8 formed in dimethyl sulfoxide solutions are compatible with the spectral fingerprints measured at high lead iodide concentrations. This finding suggests that the interpretation of optical spectra of LHP precursor solutions should account for the formation of polynuclear lead halide complexes.Low-frequency vibrations of crystalline molecules are very sensitive to the local environment in which the molecules, for example, hydrated ions captured in crystals, find themselves. We present low-temperature X-ray crystallographic measurements on the harvested thiamine crystal containing hydrated ions and its temperature-dependent terahertz spectra and synchrotron infrared microspectra. It is found from the X-ray structure that the hydrated ions and hydration water are in a similar environment to liquid, although those are captured in crystals. The vibrationally resolved THz spectra of two states in the present organic crystals containing hydrated ions are well explained by the difference in the hydrogen-bonded pattern. Peak assignments were performed based on highly accurate first-principles calculations incorporating relativistic effects and dispersion corrections. The temperature dependences are observed for the vibrations around the chloride ions and hydration water due to the loose binding of chloride ions, the bond elongation with increasing temperature, and the cleavage of weak hydrogen bonds.Water is the dominant liquid on Earth. Despite this, the main focus of supramolecular chemistry research has been on binding and assembly events in organic solvents. This arose because it is more straightforward to synthesize organic-media-soluble hosts and because of the relative simplicity of organic solvents compared to water. Nature, however, relies on water as a solvent, and spurred by this fact, supramolecular chemists have recently been making forays into the aqueous domain to understand water-mediated non-covalent interactions. These studies can benefit from the substantial understanding of the hydrophobic effect and electrostatic interactions developed by physical chemists. Nearly 20 years ago, the Gibb group first synthesized a class of water-soluble host molecules, the deep-cavity cavitands, that possess non-polar pockets that readily bind non-polar moieties in aqueous solution and are capable of assembling into a wide range of complexes with distinct stoichiometries. As such, these amphipathic host species are ideal platforms for studying the role of negatively curved features on guest complexation and the structural requirements for guided assembly processes driven by the hydrophobic effect.